1. Field of the Invention
The invention relates to a flow damper for a cleaning station, in particular for cleaning pipette tips, a cleaning liquid being introduced into the cleaning station through a pipette needle, and flowing around the pipette tip before it is conducted away out of the cleaning station, and relates to a cleaning station having such a flow damper.
2. Description of the Related Art
After processing reagents or patient samples, the pipette tips which have come into contact with them must be cleaned before they can be used for processing further reagents or samples. The pipette tips are usually cleaned in overflow cleaning stations with cylindrical overflow vessels in which a cleaning liquid is injected at a high speed through the pipette needle. The cleaning fluid accumulates there and flows around and cleans the pipette needle from the outside before it is conducted away via an overflow. Owing to the high flow speeds required for the internal cleaning of the pipette needle, severe turbulences occur in the overflow vessels, generating waves, bubbles and splashes onto the surface of the vessel. As a result, the upper isolation surfaces of the pipette needle which do not have to be cleaned and of a level detector electrode used to determine the position of the pipette needle in the cleaning station, also used at other processing stations, are also covered with liquid. Apart from the fact that this covering with liquid may lead to a carry-over of reagents or patient samples, the liquid adhering to the isolation surfaces of the pipette needle and the level detector electrode adversely affects the level detection based on a potential measurement, in that it generates a short circuit which makes reliable position measurement impossible.